SUMMARY The Administrative Core A of this Program Project is designed to provide scientific leadership, effective communication and an administrative support structure to ensure the coordination of all Program Project activities. In 2015, the four PIs of this multiple PI P01 proposal reported in Nature that hypofractionated radiation and dual checkpoint blockade activated anti-tumor T cell immunity in both mice and patients via non-redundant mechanisms, explaining the apparent synergy. This newly proposed Program Project seeks to deeply extend our knowledge regarding the intersection of radiation and immunotherapy of cancer. The proposed program has three projects and three cores, with a balance of senior leaders in multiple disciplines working alongside more junior faculty investigators as a team. We have taken advantage of the large and efficient administrative staff and the centralized research organizations at the Abramson Cancer Center (ACC) of the University of Pennsylvania to achieve our objectives. Strong institutional commitment from the ACC and Penn has helped lay the foundation for our scientific and translational achievements. The essential services provided by the Core A include: administrative support for all of the investigators in each project and core; fiscal management and oversight for all components of the Program Project; and organization and communication of all Program Project meetings and activities. The overall goal of this Core is effective and efficient leadership of the P01. The roles of the Core Director, Co-Director and administrative staff are to facilitate communication while stimulating scientific and technological interactions. In order to achieve this goal, the Core has established three objectives: (1) Establish and maintain an administrative structure to provide support for and management of all Program Project activities, (2) Foster an environment to maximize collaborative research among Program Project investigators and between other P01 and NCI initiatives, and (3) Ensure compliance with all institutional, governmental and NCI regulations and policies.